In a small bowl, mash the tofu until creamy; add to the batter. Beat the batter about 300 strokes. Fold raisins into the batter. Pour the batter into a 9-by-13-inch nonstick baking pan. Bake for 45 to 50 minutes. Cool before serving.

To rehydrate the soy protein, place it in a medium saucepan and pour the boiling water over it. Add the sloppy joe sauce; cook over low heat until heated through. To serve, pour the soy mixture over the hamburger rolls.